Manufacture of sheet metal.



No. 663,l55. Patented Dec. 4, I900.

- J. F. BUDKE.

MANUFACTURE or SHEET METAL.

(Application fll'ed Dec. 1, 1899.)

(No Model.)

HNNEALING OVEN.

COLD ROLLS.

NITED STATES PATENT OFFICE.

JOHN F. BUDKE, OF OANNONSBURG, PENNSYLVANIA.

MANUFACTURE OF SHEET METAL.

SPECIFICATION forming part of Letters Patent No. 663,155, dated December 4, 1

Application filed December 1, 1899. Serial No. 738,862. (No model.)

To all whom, it may concern:

Be it known that I, JOHN F. BUDKE, a citizen of the United States, residing at Cannonsburg, in the countyof Vt ashington and State of Pennsylvania, have invented or discovered certain new and useful Improvements in the Manufacture of Sheet Metal, of which improvements the following is a specification.

Under the present practice the sheets when they come from the hot rolls are pickled and cleaned and then annealed. After annealing the sheets are passed through what are known in the art as cold rolls, although said rolls are heated and maintained at a temperature of approximately 200 Fahrenheit. After this cold-rolling the sheets are again annealed.

As the sheets come from the hot rolls they are bent and distorted, so that they will not lie close upon each other when piled for the first annealing. By reason of this open formation the surfaces of the sheets become more or less oxidized in the annealing operation, especially near the edges, thereby forming hard spots, which prevent a uniform reduction of the sheets by the cold rolls. As the sheets are soft when subjected to cold-rollin g they will be reduced, and therefore hardened, bysuch rolling, the hardening extending through the metal of the sheets. Hence the sheets must be subjected to a thorough annealing after the cold-rolling to remove the general hardness due to the cold-rolling and the harder spots resulting from the oxidation in the annealing prior to cold-rolling. In this cold-rolling the sheets are straightened and a smooth even surface is imparted thereto, so that the sheets will lie closely and evenly upon each other. This close formation when the sheets are piled for the second annealing necessitates the maintenance of the sheets at a comparatively low temperature for a long time in order to render them soft, as if heated to a high temperature the sheets would adhere to each other.

In the accompanying drawing, forming a part of this specification, is shown diagramlnatically a form of apparatus for the practice of my invention.

In the practice of my invention the sheets as they come from the hot rolls are pickled and cleaned by any suitable pickling and cleaning apparatus, as indicated at 1, as heretofore, and are then passed through the cold rolls 2. In lieu of heating the rolls, as in the old cold-rolling method, streams of water are directed onto the rolls, as by the pipe 3, and sheets while being rolled to prevent any heating whatsoever. As the sheets are cold and the hardness imparted by the hot rolls has not been in any way relieved or modified, there will be very little, if any, reduction of the sheets by the cold rolls, the action of such rolls being almost wholly a straightening and a smoothing action. After the sheets have been cold-rolled they are arranged in piles and placed in an annealing-oven, as 4, and

subjected to a heat of about 1,800 Fahrenheit. Although the sheets are straight and smooth, and therefore form a close compact pile when arranged for annealing, they will not adhere when subjected to such a high temperature, as a very thin loose red oxid is formed on the surfaces by reason of the wetting of the sheets during the cold-rolling operation.

It is characteristic of my improved method v that one expensive annealing operation is avoided and also the injurious oxidation of portions of the sheets incident to such annealing. As a consequence of the avoidance of oxidation in the first annealing under the old method, the sheets are more homogeneous, and the sheets when finished will be more uniform in gage and in softness or ductility, and, further, as the presence of the thin red oxid coating will prevent the sheets from adhering they can be heated to a much higher temperature in annealing, thereby rendering the sheets softer and more ductile than in the old method and in much shorter time.

I claim herein as my invention 1. As an improvement in the art of manufacturing sheet metal, the method herein de-' featuring sheet metal, the method herein de- In testimony whereof I have hereunto set scribed, which consists in pickling and cleanmy hand.

in the sheets 'asthey come from the hot rolls, cold-rolling the sheets, Wetting the rolls and JOHN BUDKE' sheets during the rolling operation, and -an- Witnesses: nealing the rolled sheets, substantially as set DARWIN S. WOLOOTT, forth. i F. E. GAITHER; 

